ASoC: SOF: amd: Add psp_mbox_ready() and psp_send_cmd() callback

We need to ensure if PSP is mbox ready before and after sending cmd
to PSP over SMN interface. Add method to check MBOX_READY bit of PSP
with some delay over ACP_PSP_TIMEOUT_COUNTER. Replace psp_fw_validate
with new method psp_send_cmd() to send command via psp mailbox.
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Ajit Kumar Pandey <AjitKumar.Pandey@amd.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20220421165820.337207-2-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/amd/acp.c

@@ -138,14 +138,18 @@ int configure_and_run_dma(struct acp_dev_data *adata, unsigned int src_addr,
 	return ret;
 }
 
-static int psp_fw_validate(struct acp_dev_data *adata)
+/*
+ * psp_mbox_ready- function to poll ready bit of psp mbox
+ * @adata: acp device data
+ * @ack: bool variable to check ready bit status or psp ack
+ */
+
+static int psp_mbox_ready(struct acp_dev_data *adata, bool ack)
 {
 	struct snd_sof_dev *sdev = adata->dev;
 	int timeout;
 	u32 data;
 
-	smn_write(adata->smn_dev, MP0_C2PMSG_26_REG, MBOX_ACP_SHA_DMA_COMMAND);
-
 	for (timeout = ACP_PSP_TIMEOUT_COUNTER; timeout > 0; timeout--) {
 		msleep(20);
 		smn_read(adata->smn_dev, MP0_C2PMSG_26_REG, &data);
@@ -153,8 +157,38 @@ static int psp_fw_validate(struct acp_dev_data *adata)
 			return 0;
 	}
 
-	dev_err(sdev->dev, "FW validation timedout: status %x\n", data & MBOX_STATUS_MASK);
-	return -ETIMEDOUT;
+	dev_err(sdev->dev, "PSP error status %x\n", data & MBOX_STATUS_MASK);
+
+	if (ack)
+		return -ETIMEDOUT;
+
+	return -EBUSY;
+}
+
+/*
+ * psp_send_cmd - function to send psp command over mbox
+ * @adata: acp device data
+ * @cmd: non zero integer value for command type
+ */
+
+static int psp_send_cmd(struct acp_dev_data *adata, int cmd)
+{
+	int ret;
+
+	if (!cmd)
+		return -EINVAL;
+
+	/* Check if PSP is ready for new command */
+	ret = psp_mbox_ready(adata, 0);
+	if (ret)
+		return ret;
+
+	smn_write(adata->smn_dev, MP0_C2PMSG_26_REG, cmd);
+
+	/* Check MBOX ready as PSP ack */
+	ret = psp_mbox_ready(adata, 1);
+
+	return ret;
 }
 
 int configure_and_run_sha_dma(struct acp_dev_data *adata, void *image_addr,
@@ -196,7 +230,7 @@ int configure_and_run_sha_dma(struct acp_dev_data *adata, void *image_addr,
 		return ret;
 	}
 
-	ret = psp_fw_validate(adata);
+	ret = psp_send_cmd(adata, MBOX_ACP_SHA_DMA_COMMAND);
 	if (ret)
 		return ret;